Metal clay
Metal clay o Precious metal claywww.metalclay.com, is a clay-like medium used to make jewellery, beads and small sculpture. It consists of very small particles of metals (such as silver, gold, platinum, or copper) mixed with an organic binder and water. Alloys such as bronze or steel are also available. Metal clay can be shaped just like any soft clay, by hand or using moulds. After drying, it can be fired in a variety of ways including in a kiln, with a handheld gas torch, or on a gas stove. The binder burns away, leaving the pure, sintered metal. Shrinkage of between 8% and 30% occurs (depending on the product used), but this is exploited by artisans to produce very fine detail. Silver metal clay results in objects containing 0.999 pure silver - aka fine silver, which is ideal for enameling. Although gold metal clay is much more expensive to use, the color and richness is phenomenal. It can be used to make stunning solid gold objects or used sparingly to make beautiful accents on silver pieces. Lump metal clay is sold in sealed packets to keep it moist and workable. The silver versions are also available as a softer paste in a pre-filled syringe which can be used to produce extruded forms, in small jars of slip and as paper-like sheets, from which most of the moisture has been removed. There are two popular brands of silver metal clay, Precious Metal Clay (PMC) and Art Clay Silver (ACS). Precious Metal Clay or PMC was developed in the early 1990s in Japan by metallurgist Dr. A. Morikawa Introduction to Precious Metal Clay by Mary Ann Devos ©2003 published by Wardell Publications Inc (ISBN 0-919985-36-X). The material consists of microscopic particles of pure silver or fine gold powder and a water-soluble, non-toxic, organic binder which burns off during firing. Success was first achieved with gold, and later duplicated with silver. The original formula of PMC, now called "Standard", must be fired in a kiln at and has a shrinkage rate of 30%. Mitsubishi Materials Corporation, a subsidiary of Mitsubishi, later developed two additional versions of silver called "PMC+" which can be fired as low as for 30 minutes, and "PMC3", which can be fired as low as for 45 minutes. Both PMC+ and PMC3 have a shrinkage rate of 12-15% and may also be fired with a handheld torch for 4–7 minutes. A 22k gold gilding material called "Aura 22", and lump 22k yellow gold clay (an alloy of fine silver and gold) are also available.McCreight, Tim. "What's New?" Metalsmith Spring 2006, Vol. 26 Issue 1, p42-45, 4p PMC also manufactures an 18k gold clay and a platinum clay, but these latter two are only marketed in Japan. Art Clay Silver or ACS was developed by AIDA Chemical Industries, another Japanese company. Art Clay followed PMC Standard with their Art Clay Original clay (more like PMC+ than PMC Standard), which allows the user to fire with a handheld torch or on a gas hob. Due to subtle differences in the binder and suggested firing times, this clay shrinks less than the PMC versions, approximately 8-10%. Further developments introduced the Art Clay Slow Dry, a clay with a longer working time. Art Clay 650 and Art Clay 650 Slow Dry soon followed - both clays that can be fired as low as , allowing the user to combine the clay with glass and sterling silver which are affected negatively by the higher temperatures needed to fire the first generation clays. AIDA also manufacturers Oil Paste, a product only used on fired metal clay or milled fine silver, and Overlay Paste, which is designed for drawing designs on glass and porcelain. In 2006 AIDA also introduced the Art Clay Gold Paste, a more economical way to work with gold. The paste is painted onto the fired silver clay, then refired in a kiln, or with a torch or gas stove. When fired it bonds with the silver, giving a 22ct gold accent. The same year also saw Art Clay Slow Tarnish introduced, a clay which tarnishes less rapidly than the other metal clays. Lump metal clay in bronze was introduced in 2008 by Metal Adventures Inc. and in 2009 by Prometheus. Lump metal clays in copper were introduced in 2009 by Metal Adventures Inc., and Aida. Due to the lower cost, the bronze and copper metal clays are currently used by more artists than the gold and silver metal clays. Base metal clays, such as bronze, copper, and steel metal clays are best fired in the absence of oxygen to eliminate the oxidation of copper by atmospheric oxygen. A simple means to accomplish this (place the pieces in activated carbon inside a container) was developed by Bill Struve. Do-it-yourself versions such as Silver Smiths' Metal Clay Powder (silver) are available in a dry powder form to which the user adds water to obtain any desired consistency. Hadar's Clay powder can be purchased in bronze, copper, and steel. Claymania Art Clay, Inc. developed, manufactures and sells a dry, powder form of Metal Mania Metal Clay - Bronze and Copper Clay metal clays. Notes External links * Art Clay Silver Society * PMC Guild * Metal Clay Artist Magazine fr:Pâte à métaux précieux ja:銀粘土 Categoría:Diccionario de cerámica inglés - español: M Categoría:Sculpture techniques Categoría:Jewellery making Categoría:Diccionario M